Automated handling devices, such as industrial robots, are used for very varied tasks in modern industrial practice. It is often necessary for several robots, in each case controlled by a robot control, to perform in time-matched manner, i.e. synchronously certain handling actions. For this purpose it is generally necessary for certain operating actions to be simultaneously performed on a plurality of robot controls. Said operating actions can e.g. be the distribution of a starting command for a group of cooperating robots. In addition, certain commands are regularly linked with state conditions, which must be fulfilled on all the controls before a specific control command or program instructions initiated by the latter can be synchronously performed by a plurality of robot controls.
US 2002/0029095 A1 (corresponding to EP 1 186 286 A2) discloses a synchronous control of cooperating robots, in which one robot control functions as the master and further robot controls as slaves. The master control transmits start commands and both position and interpolation data to all the slaves and then, following the reply or acknowledgement, perform synchronous movement or control sequences with respect to a starting time. In the case of a stop command of one of the cooperating robots, all the participating robots are decelerated in accordance with an identical stopping process.
A particular disadvantage of the known control is the rigid master-slave concept, according to which at the start of a flow process one of the robots must be established as master for said process. This greatly restricts the usability of such a control. All participating robot controls contain a plurality of distinct control programs (master program, slave program, normal program), whose interaction must be determined beforehand and leading to increased programming and administration effort and expenditure, together with a corresponding, additional storage expenditure. Further disadvantages result from the data-complicated and error-prone transmission of extensive position and interpolation data referred to in the aforementioned document and necessary therein for synchronous control purposes.
Whilst avoiding the aforementioned disadvantages, the object of the invention is to provide a method or apparatus for the synchronous control of a plurality of handling devices, such as industrial robots, which is simply constructed and flexibly usable, whilst ensuring a reliable process sequence.